This invention relates to a load cell which is generally a device for providing an electrical output proportional to a force applied to the cell.
Load Cells are used in widely different locations but one particular common type of cell includes a body formed from a single block of material which has various openings cut in the block so the whole block can distort when a load is applied at one end. This distortion is measured by strain gauges mounted within the body of the block with the strain gauges arranged in conjunction t with a bridge circuit so that they provide an output proportional to the load applied.
Load Cells of this type have been widely used for many years and represent the standard in the industry at the present time. They do however have a number of severe disadvantages. Firstly the device is expensive to manufacture since it requires recesses to be formed in the block which are of a complex shape and which are manufactured to close tolerance to provide the necessary deformation characteristics. Secondly the load cell is only responsive to forces within a predetermined range and therefore it is necessary to manufacture various load cells of differing sizes to accommodate different ranges of force. This again increases cost in view of the necessity of manufacturing and holding a wide range of inventory. Thirdly the application of a load greater than the predetermined range to the block can cause deformation of the block beyond its elastic limit and thus the device is effectively destroyed and requires replacement.